At standard temperature and pressure, a given sample of water vapor occupies a volume of 2.80 L. How many moles of water vapor are present
A) 0.145 mol
B) 0.135 mol
C) 0.125 mol
D) 0.115 mol
E) None of the above

Question

Quizplus · Accepted Answer

At standard temperature and pressure (STP), 1 mole of an ideal gas occupies 22.4 L. Therefore, the number of moles of water vapor is calculated by dividing the volume by the molar volume at STP: 2.80 L / 22.4 L/mol = 0.125 mol.

At Standard Temperature and Pressure, a Given Sample of Water